The NEC 2014 and, respectively, the upcoming 2017 code changes have many photovoltaic companies concerned. There are many uncertainties associated with photovoltaic systems and building fires. A report of having to let a building go down in a “controlled burn” because the photovoltaic system is installed creates anxiety among owners and firefighters. German firefighters have had to fight the same battle for several years now, and as a result they created detailed requirements for PV system shut down. Kautzor Enterprises Inc. (KEI) has found a reliable solution and product, the Eulektra FireSec Switch.
Individual solar panels continuously produce direct current, even if the inverter is disconnected. The combined voltage of a string of panels can be very dangerous. This does pose a serious threat for firefighters; even 120 V carries considerable risk. With the FireSec Switch individual solar panels can safely be separated from the DC circuit and inverters separated from the public grid. The Eulektra FireSec Switch is an electrical extension for photovoltaic systems. It consists of a series of compact high power relays placed between the individual panels and a circuit breaker between inverter and grid.
The FireSec Switch system can be triggered automatically by smoke detectors or manually by the firefighter. In case of a fire, the system first disconnects the inverter from the grid and then with a short delay, the individual solar modules from the DC circuit. By disconnecting the DC circuit at the input and the output side of each module, it is ensured that the entire conduit is free of any dangerous voltage. The switching sequence allows the use of predominately compact relays; thus minimizing the resistance in the phase of power production.
“Making sure the emergency shutdown works properly in any situation was our first priority during development,” explains Eulektra CEO Siegfried Hain. The system is controlled through an autonomous line and can be activated manually or automatically by connecting it to a fire alarm. Thanks to a dormant current, the solar system will be separated from the circuits even when the control cable is damaged.
Furthermore and in accordance with Eulektra’s security concept, a nighttime automated service activates a circuit breaker every evening after sunset. This feature tests and monitors the mechanical functionality of the relays. The components of Eulektra’s FireSec Switch fit all modern solar modules. Retrofitting existing systems with the Eulektra FireSec Switch can easily be done by a trained and experienced installer.
Stefanie B. says
Looks like a great product. Is it available in the U.S.?